Physical Sciences and Mathematics Commons^™

Catalytic Oxidation Of Trace Concentrations Of Trichloroethylene Over Cr2o3 And 5% Cr2o3 On ?-Al2o3, Soyoung Myung

Theses

This research addressed the ability of Cr₂O₃ and 5% Cr₂O₃/γ-Al₂O₃ to catalytically oxidize trichioroethylene (TCE). Various types of Cr₂O₃ catalysts were compared with Pt, CuO and Fe₂O₃ which were previously tested in our laboratory. A number of sample catalysts containing 5% Cr₂O₃ on γ-Al₂O₃ were synthesized for this research. Different procedures were evaluated in the synthesis in order to find which procedure gives the most active catalyst. The oxidation of TCE was used as a diagnostic reaction to …

Effectiveness Of Sediment Control Structure : Reducing Nonpoint-Source Pollution Entering A Rural Housing Development Lake In Mercer County, Pennsylvania, Elaine K. Brenner

Theses

For the past two decades, water quality of both natural and man-made lakes has been a major environmental concern. Numerous studies suggest that land use patterns and/or storm water runoff are major factors in nutrient loading and bacterial contamination of freshwater lakes. In 1986, the Property Owners Association at Lake Latonka in Jackson Center, Pa., installed three sediment control structures in an attempt to reduce the amount of nonpoint-source pollution entering the lake. The Association installed a fourth structure in 1988. It has yet to be determined if any improvement in the water quality has occurred due to the control …

Synthesis And Characterization Of Silicon Dioxide Thin Films By Plasma Enhances Chemical Vapor Deposition From Diethylsilane And Nitrous Oxide, Lan Chen

Theses

This study is focused on the synthesis and characterization of silicon dioxide thin films deposited on silicon wafers by plasma enhanced chemical vapor deposition(PECVD), using diethylsilane (DES) as a precursor and nitrous oxide (N₂O) as the oxidant. The process parameters, such as temperature, pressure and reactant gas composition have been systematically varied and their effects on the film growth rate and properties were investigated. The growth rate was found to be inversely proportional to the temperature in the examined range of 100-300°C. It increased with increasing N₂O/DES flow rate ratio as the total flow rate increased …

Application Of Approximate Graph Matching Techniques For Searching Databases Of Two-Dimensional Chemical Structures, Karen R. Pysniak

Theses

This paper proposes the application of approximate graph matching techniques for best-match searching of two-dimensional chemical structure databases based upon topology. Chemical structures are represented as labeled graphs, each atom a node in the graph and each bond an edge. By inserting; deleting and renaming nodes/edges, one structure may be transformed into another. We define similarity as the weighted sum of the costs of these edit operations. An algorithm for approximating the minimum distance between two graphs based on simulated annealing is applied. Best-match searches are performed utilizing this pre-computed distance information and applying the concepts of triangle inequality to …

Ultrasonic Enhanced Soil Washing, Chu-Feng Wei

Theses

Soil washing is an ex-situ process employing chemical and physical extraction and separation techniques to remove a broad range of organic, inorganic, and radioactive contaminants from soils. This research investigates the enhanced soil washing of a high level Polycyclic Aromatic Hydrocarbons (PAHs) contaminated coal tar soil by the application of ultrasound energy coupled with surfactant (soap) emulsions and attempts to optimize pollutant removal from contaminated soils. The non-ionic surfactant, octyl-phenyl-ethoxylate, was used as the surfactant.

Using bench-scale experiments, the magnitude of the ultrasonic enhancement was evaluated by changing the process parameters, such as ultrasonic power density, Dwell (extractor residence time), …

Factors Effecting Calcification Of Bioprosthetic Heart Valves, Sumei Yu

Theses

Calcification is the most frequent cause of clinical dysfunction of glutaraldehyde treated bioprosthetic heart valves. In this study, we compared calcification of bioprostheses of the No-ReactTM and the conventional glutaraldehyde treated pericardium by both in-vivo and in-vitro methods, and to further delineate the role of the host's inflammatory response in implant degeneration.

In the in-vitro study, the two types of pericardial samples were placed in individual polystyrene tubes containing physiological concentrations of calcium and phosphate and incubated for 21 days at 37°C. In the in-vivo study, the two types of pericardial samples were implanted subcutaneously in rats and subsequently retrieved …

Investigation Into Fracture Behavior And Longevity Of Pneumatically Fractured Fine-Grained Formations, Heathe Ann Hall

Theses

This study investigates volume changes in fine-grained soil formations and their effect on pneumatically induced fractures. Pneumatic fracturing is an enhancement technology for in situ remediation of hazardous waste sites, which increases the formation permeability by creating fractures. A number of formation properties and environmental conditions which affect fracture aperture were identified in this study.

Laboratory experiments were performed with control devices to investigate idealized fracture flow under linear and radial flow geometries. These tests exhibited cubic law behavior, and gas compressibility was seen as a measurable effect. A horizontal infiltrometer device was successfully developed to induce and control volume …

Management Of Hospital Wastes In The United Arab Emirates, Hanan Ahmed Ali Shuwaiter

Theses

The gradual expansion and development of new public and private medical complexes have resulted in the production of various types of wastes which include hazardous materials. Such wastes require appropriate handling and management schemes based on safer disposal methods. There are no reliable figures for quantifying the amount of medical waste generated or appropriate legislation and guidelines for handling, storage, transport and disposal of medical waste in the United Arab Emirates. No previous detailed studies have been conducted for the management of medical waste in the UAE. In general there is insufficient awareness of the health hazard associated with improper …

Epidemiological Study Of Road Traffic Accidents, Casualties And Fatalities In The United Arab Emirates, Ahmed Saif Al-Falasi

Theses

In the United Arab Emirates (UAE), with its rapid expansion of road construction and increase in the number of vehicle, road traffic accidents are becoming a serious public health problem. It was aimed to study road traffic accidents (RTA) in view of the fact that cause a substantial waste of national resources which could be used fruitfully for the improvement of health schemes and other aspects of life in UAE. It was observed that there has been a dramatic increase in the number of registered vehicles during this period. During the ten years period 1983 to 1992, the population of …

Heavy Minerals And Metals Content Of Coastal Sediments Between Dibba And Kalba, Eastern Coast (U.A.E.)., Aisha Hader Juma

Theses

The present project deals with the study of coastal sediments along the Eastern Coast of United Arab Emirates (U.A.E.), and it has two main objectives:

• Determination of heavy mineral contents of the coastal sediments in relation to the geology of the hinterlands.
• Trace metals studies (Zn, Pb, Ni, Cr, Cu, Co, Cd, Mn and organic carbon) as a measure of environmental pollution.

The results of heavy minerals separation (fine sand fraction) from the Eastern Coast sediments reflect that these sediments are generally rich in heavy minerals content with percentages reaching up to 78% with some areas reaching upto 98%. The …

Analysis Of The Oxidation Of Isotox By Immobilized Bacteria, Chad Sheng

Theses

The purpose of this work is to show the effects of bio-oxidation of a pesticide through a spiral wound bioreactor using immobilized mixed culture bacteria. The pesticide used for this study is Isotox® and its active ingredients are acephate or O,S-dimethyl acetylphosphoramidothioate and vendex or hexakis (2-methyl-2-phenylpropyI)- distannoxane. Qualitative analysis of the product indicated presence of sulfate.

A consistent and unique DO pattern for Isotox^® showed at least 4 minima, whereas phenol has only one minimum. The consistency of the DO pattern for Isotox^® has been observed for over 30 injections into the bioreactor system. For both an …

Microaccelerometer With Mechanically-Latched Memory, Zhenyu Ma

Theses

A new mechanically-latching micromachined accelerometer is designed in this thesis based on the large deflection of a microcantilever beam. This surface micromachined device moves in the plane of the substrate surface. This device is surface micromachined with no backside etching needed. The interaction of the friction tether and the dimensions of the cantilever beam have been modeled and calculated. The design acceleration sensitivity range is from 100G to 1000G. The photomask set has been designed by using the Mentor Graphics system. The dimension of individual accelerometers ranges from 100 to 1000 micrometers in length to tens of micrometers in width. …

Silicon Optical Fiber Pressure Sensor, Jian Pan

Theses

A novel optical fiber pressure sensor based on a micromachined thin silicon diaphragm is proposed. Detail descriptions of the sensor structure, modulation principle and fabrication process are given.

The device operates on the following principle: Pressure deflects a silicon diaphragm which moves the output end of a light source fiber. The emitted light intensity is picked up and shared by two receiving fibers placed side by side. The variation of the intensity ratio in the receiving fibers caused by the relative motion of the emitting fiber can be easily converted to a linear signal versus the deflection of the silicon …

Requirements, Design And Business Process Reengineering As Vital Parts Of Any System Development Methodology, Alicja Ruszala

Theses

This thesis analyzes different aspects of system development life cycle, concentrating on the requirements and design stages. It describes various methodologies, methods and tools that have been developed over the years. It evaluates them and compares them against each other. Finally a conclusion is made that there is a very important stage missing in the system development life cycle, which is the Business Process Reengineering Stage.

Removal Of Chlorinated Hydrocarbons From Water By Air Stripping And Solvent Sublation, Alpana Gami

Theses

Removal of trichloroethylene, monochlorobenzene and 1,3 dichlorobenzene from water by air stripping and solvent sublation into an organic phase was investigated. The sublation solvents used were paraffin oil and decyl alcohol. The rate of removal from water by solvent sublation and air stripping was highest for trichloroethylene, followed by chlorobenzene and finally 1,3 dichlorobenzene. For the three compounds, solvent sublation had the greatest advantage over air stripping in the reduction of emission of the compounds to the atmosphere. For the three compounds, the removal was enhanced at higher flowrate in both air stripping and solvent sublation. For the removal of …

Catalytic Oxidation Of Trichloroethylene Over 5% [Alpha]-Fe2o3/[Gamma]-Alumina On A Honeycomb Monolith, Jeongho Han

Theses

This study addresses the ability of iron oxide to catalytically oxidize low concentrations of trichloroethylene (TCE) with air. The catalytic oxidation of trichloroethylene in a tubular reactor system was evaluated experimentally as a function of temperature and space velocity. A gas chromatograph with electron capture and flame ionization detectors was used for quantitative analysis of feed and product streams. X-ray diffraction measurement were used to qualitatively analyze the catalyst. The result indicate that over 99% conversion of 109 ppmv trichloroethylene in air is achieved at 1,490 v/v/hr and 450 °C, and at 21,768 v/v/hr, 550 °C. The major products from …

A High Temperature Pressure Sensor Based On Magnetic Coupling And Silicon Wafer Bonding, Deguang Zhu

Theses

In this thesis, the design and fabrication of a bulk micromachined and wafer bonded pressure sensor for high temperature applications is described. The device design is based on the magnetic coupling principle as described by the Biot-Savart law. By combining the mechanical properties of single crystal silicon with magnetic coupling, the designed sensor can be operated up to 600°C. The key components within the sensor are two inductive coils, a silicon diaphragm and a hermetic vacuum cavity.

The modeling based on a nine-turn single level coil device and a 300 μm x 300 diaphragm indicates an output rms voltage range …

Bioremediation Of 2-Chlorophenol In A Laboratory Soil Column, Timothy A. Coon

Theses

In-situ bioremediation offers the prospect of rendering organic contaminants harmless without having to remove them from the subsurface. It involves the modification of environmental factors to stimulate the biodegradation of chemicals in the subsurface by microorganisms. However, for the cost-effective use of in-situ bioremediation, it is necessary to develop accurate engineering models to quantify biodegradation.

In this thesis, the biodegradation of 2-chlorophenol in a laboratory soil column was examined in order to experimentally verify an engineering model. Experiments were performed to obtain the physical and biological parameters required by the model, and the steady-state 2-chlorophenol distribution in the column.

A …

The Growth, Enrichment, And Dehalogenating Properties Of Pyrococcus Gbd And Desulfurococcus Sy, Siegfried Georg Mueller

Theses

Recent investigations of volcanic smoker chimneys along the Atlantic Rift has lead to the discovery of hyperthermophilic bacteria. In particular, Pyrococcus GBD and Desulfurococcus SY were studied, optimizing growth conditions. This was achieved using elemental sulfur amendments, artificial sea water, and dehydrated marine broth. The microbes were then acclimated to enriched cultures containing 2,4,6 trichlorophenol in 0.0126 mM, 0.063 mM, and 0.126 mM amendments. The amended cultures showed dehalogenating properties and were subjected to a data qualifying program. This program indicated that the dehalogenation was a function of microbial gowth. A mass balance experiment showed that both microbes were able …

Quantitative Studies Of An Immobilized Cell Oxidative Bioreactor, Timothy Lance Borkowski

Theses

The purpose of this work was to determine a suitable method of utilizing dissolved oxygen in reservoir solution data to quantitatively measure the amount of oxygen and substrate consumed for an immobilized cell batch bioreactor in a recirculation configuration. Statistical analysis was performed on multiple phenol injections to determine the mathematical relationship between dissolved oxygen readout and the amount of phenol degraded.

Factors considered in the mathematical analysis include amount of substrate degraded, reaction time, recirculation flow rate, measured dissolved oxygen concentration and oxygen consumption, oxygen conversion per pass through the bioreactor during steady state, and vitality of the microorganisms. …

Off-Line Hand-Printed Chinese Character Recognition Based On Stroke Matching, Sunshine Chang

Theses

The specific purpose of this thesis is the automated recognition of the off-line Chinese hand-printed characters by using a blue ball-point pen. Through mask processing, the main components in a Chinese character such as vertical, horizontal, and slant strokes can be extracted. Then, the connected components with the coordinates of the top, bottom, leftmost, and rightmost ends of each stroke extracted are found. From these coordinates, the length and position of each stroke can be computed.

According to the number, relative length, and relative position of each stroke, both of the coarse and fine rule-based classification can be made, and …

Ultra-Thin Silicon Wafer Bonding, Diyu Yan

Theses

In this thesis the history and recent developments on the silicon direct bonding technique are reviewed. The growing applications of this technique in SOI, SOS and MEMS areas, difficulties and disadvantages of various bonding processes are discussed. A direct bonding procedure for attaching ultra-thin wafers less than 200 μm thick to substrate wafers is developed and described in detail. Difficulties in handling, aligning and annealing ultra-thin wafers are reported. Wafers of different doping concentration, thickness, surface roughness and chemical characteristics are tested for bondability. Methods to minimize voids and other failure mechanisms are proposed. A photodetector is designed based on …

The Analysis And Isolation Of Diarrhetic Shellfish Poisoning Toxins, Seán S. Kelly

Theses

This research was initiated to examine the Diarrhetic Shellfish Poisoning (DSP) toxin profiles in mussels (Mytilus edulis) in south-west Ireland. Extensive sampling and testing of shellfish was conducted during the toxic periods of 1991 to 1994. This was the most comprehensive study ever undertaken of toxin profiles in shellfish from a single cultivation area.

A new toxin named dinophysistoxin-2 (DTX-2), which is an isomer of okadaic acid (OA), was the major toxin during prolonged DSP episodes. This toxicity in shellfish occuired soon after high cell counts of Dinophysis acuta were observed. As well as seasonal variability in toxin levels, substantial …

Seroprevalence Of Toxoplasmosis Amongst Healthy Adults In The Al Ain Area, Hamad Noor Mohamed Ahmad

Theses

There being no published data on the seroprevalence of toxoplasmosis in the UAE, a base -line study was carried out on a randomly selected population of healthy adults drawn from subjects presenting themselves for a health certificate at the Department of Preventive Medicine, Al Ain, or presenting for blood donation at the two main hospitals in Al Ain, the Tawam Hospital and Al Ain Hospital. Commercially available VIDAS IgG and IgM kits were used to test for seropositivity. A validated questionnaire was used to record personal data and blood was drawn from each donor after informed consent. All raw data …

Determination Of Heavy Metals In Sheary Fish Lethrinus Lentjan Imperors (Family: Lethrinidae “Teleost”) In United Arab Emirates Water, Maryam Hareb Al-Yousuf

Theses

Investigation of heavy metals in fish is an important aspect of environmental pollution as human activities contribute to the progressive increase in the concentration of metals in the environment as well as aquatic system. Therefore, an analytical survey for the contents of copper, zinc, manganese, and cadmium in liver, heart, kidney, muscle and skin of Lethrinus lentjan, collected from the western coast of the United Arab Emirates (Ras AI-Khaima) was carried out. The range and mean values of the levels of metals were determined and compared with the reported values in the Arabian Gulf.

Significant concentrations of the elements …

Volatilization Of Contaminants From Wastewater, Shaoyan Wu

Theses

Emission of volatile organic compounds (VOCs) from many industrial wastewater treatment facilities are a major source of air pollution, and getting much attention from EPA. In order to determine "Best Available Control Technology" and "Lowest Achievable Emission Rate" for controlling emissions of VOCs from industrial wastewater, the accurate estimation of VOCs emission rate and realistic modeling of contaminant volatilization are required.

In this research, the volatilization of three compounds (Toluene, Xylene, and Aniline) were studied under varying aeration, stirring, and quiescent scenarios. The concentrations of contaminant were analyzed by HPLC. Experimental rate constants were obtained by using the first order …